In partial onset epilepsy, seizures arise focally in the brain and often propagate. Patients frequently become refractory to medical management, leaving neurosurgery, which can cause neurologic deficits, as a primary treatment. In the cortex, focal seizures spread through horizontal connections in layers II/Ill, suggesting that severing these connections can block seizures while preserving function. Focal neocortical epilepsy was induced in mice, sub-surface cuts were created surrounding the seizure focus using tightly-focused femtosecond laser pulses, and electrophysiological recordings were acquired at multiple locations for 3-12 months is induced. Cuts reduced seizure frequency in most animals by 87%, and only 5% of remaining seizures propagated to the distant electrodes, compared to 80% in control animals. These cuts produced a modest decrease in cortical blood flow that recovered and left a 20-um wide scar with minimal collateral damage. When placed over the motor cortex, cuts did not cause notable deficits in a skilled reaching task, suggesting they hold promise as a novel neurosurgical approach for intractable focal cortical epilepsy.